She said Michelle O'Neill, Sinn Féin's new northern leader, had been "hand-picked by Gerry Adams to do his bidding in Northern Ireland".

On the subject of the botched Renewable Heat Incentive (RHI) scheme, which may cost NI taxpayers as much as £490m, the DUP leader said it was "not the cause, but it did become the excuse for this election".

"I know that the investigation into the RHI scheme will clear my name," she said.

Mrs Foster was enterprise minister when the scheme was set up in 2012; it was intended to increase the creation of heat from renewable sources.

However, businesses have been receiving more in subsidies than they are paying for renewable fuel and the scheme became highly oversubscribed.

In a statement, the UUP leader Mike Nesbitt said: "The DUP are engaged in a massive game of distraction.

'Incompetence and sleaze'

"This is the same rhetoric which they sold to the electorate last May and look where we are now.

"It is the last refuge of a party leaving behind a legacy of incompetence and sleaze.

"The DUP and Sinn Féin have been in government for ten years and people are still being called back to the trenches. We want partnership government."

SDLP assembly candidate Patsy McGlone also commented: "The Irish language belongs to no party, it belongs to no community, it is a communal element of our rich cultural inheritance and that cannot be diminished by anyone.

"Today's comments, rooted in the politics of division and hate stand in stark contrast to the opportunity to embrace cooperation and compromise for the common good that this election offers.

"Whatever happens, at the far side of the election, the need for statutory protection for Irish language speakers is all the more important."

Alliance Party leader Naomi Long told BBC News NI she did not think that Mrs Foster's language was appropriate for someone "who is going to the electorate to ask to be the leader of an entire community, and that is what the first minister's job is".